bleeding stain, or not?

ok so long story short im working on a project which involves building a guitar, fake but still basicly a guitar and because of my extremely novice skill but because of my addiction for crash course learning rather then starting easy and building up from there it seems i must think about doing something that could be fairly simple, then bringing it to an impossible level and scaling back so theres a hint of reality within the realm…
so not knowing the terms for most of what goes on in here, i cant seem to find the glossary around here..lol but so i have a guitar neck with a fretboard glued to it but the problem was/is i wanted walnut but not wanting to spend the afternoon/evening planing down a 3/4” into a 1/4” i decided to hit menards who had only oak in 1/4” and 1/2” so i settled for oak and grabbed some walnut tung oil, so i realized at 1st id couldnt glue the fretboard to the neck until i had it shaped into what i needed i decided to clamp it and try and shape it that way, which i discovered was maybe not the best pla, or maybe just not the best operator but regardless so i ended up glueing the fretboard to the neck and got it all shaped but now im wondering, how will i get the tung oil to stay away from the maple neck and only stay on the oak fretboard, im sure tape would bleed it over and maybe the glue will seal it to keep it from bleeding into the maple, im kind of a bit confused about this situation right now so if anyone has dealt with a similar issue or knows any tips or tricks, im open to suggestions!

-- if you dont have it, build it, especially when its a stupid idea